Certain elevators apply a drive mechanism based on a rack-and-gear system (also referred to as rack-and-gear elevators). A motor mounted on an elevator car drives a gear the teeth of which engage a toothed rack secured to a wall of an elevator shaft. Such a system is illustrated in WO-A1-2010/010023. Drawbacks of rack-and-gear elevators include noise generated when the gear teeth move along the rack and relatively poor ride comfort. For these reasons, rack-and-gear elevators are typically used in areas where noise and ride comfort are not critical such as the building industry or other industrial applications. For example, T. Grovatt and J. Tiner describe in “Rack-and-Pinion Gear-Drive System for Spires of Steel,” Elevator World, September 2006, Vol. LIV, No. 9, pages 79-83, a dual pinion drive and an integral I-beam rail and rack system for use in outdoor broadcast towers.
Despite these drawbacks, a rack-and-pinion elevator does not need a drive machine located in an overhead space or a machine room. Further, a rack-and-gear elevator does not require a counterweight traveling along the elevator shaft. Rack-and-gear elevators, therefore, require less space than, for example, conventional traction elevators. For these reasons, rack-and-gear elevators are attractive for non-industrial uses.